Swift Airframe - Vertical/Rudder

VERTICAL STAB BEEF-UP???  (090200)
From: Bill Doty <wdoty@seidata.com>
Via: Yahoo! "Globe Temco Swift Club"
I have been told there is an AD on the trailing edge of vertical stabilizer. Stiffeners of some sort. Can someone fill me in on this. While the rudder is off is a good time to comply.  Thanks, Bill Doty

Bill,
No, there is no AD on the vertical stabilizer. There were doublers available to beef up the stabilizer, but they are no longer available. They are a little harder to make than you might think because the spar is curved and the doublers must be made from 2024-0 and formed then heat treated later. Inspect your spar and perhaps replace the rivnuts for the fairings with regular 6-32 AN stopnuts. -- Jim

RUDDER CABLE TENSION...(120200)
Subj: Rudder Cable Tension.
From: David Haley <daha2@home.com>
Hello Jim, I am starting the annual on 2337B. The right rudder cable needs to be re-tensioned. I cannot find the value to use for the cable. Can you help? Thanks in advance. David Haley, N2337B

Dave,
Um, don't you have the Swift Operator's Handbook? On page 30 all the cable tensions are listed. The rudder cables are tensioned to 70 lbs. -- Jim

TAIL SECTION REPAIRS... (040401)
From: Darrel S. Kester <dskester@worldnet.att.net>
Subject: Questions for "Monty the Answer Man"
Dear Monty,
In the process of getting N80576 (Sn 79) back in the air, I have removed the empenage for repairs to the horizontal stabilizer (loose, defective and missing rivets to the front and rear carry through). I thought would take the opportunity to reinforce the vertical stabilizer and beef up the Horizontal stabilizer rear spar attachment fitting with a chrome molly replacement. (reference: page 50 - Maintenance and Operation for the Swift) I have a couple of questions in regard to having this part machined. The aluminum part which I removed from the plane has the main top hole drilled 3 1/2 inches above the four bottom carry through holes. This main attachment hole is also 1/4 inch off of center. In general the holes are not drilled symmetrically or in parallel. I do not know if this part is original but I suspect that this might be a replacement part made sometime during the last 50 years. In having this part made, placing the bottom holes in the exact position would make sense but where to place the top hole has me baffled. Should I lower the hole as suggested on page 50 since my plane is now converted to 145hp. And if I lower the hole, how much. And should this hole be placed off center like the existing part or is the hole drilled in place.
If I might, I would like to ask another question. I have seen a mechanical gear position indicator which was a simple "L" shape extension attached to the landing gear door. Do you know if these gear indicators can be bought or must one fabricate the indicator. I imagine it is the latter situation which would require that I would need the dimensions and a field approval. Thank you, Monty, in advance. Your wealth of information and your willingness to share is deeply appreciated by fledgling Swift Owners like myself. Darrel S. Kester dskester@worldnet.att.net

Darrel,
I would repair any loose, defective or missing rivets of course, but I have reservations about beef-ups. The rear fitting can be replaced with a chromemoly bracket without much chance for a negative result if proper methods are used to prevent dissimilar metal corrosion. In the new AC43.13-1B the FAA cautions against beefing up structure without engineering, noting that it will then break somewhere else. I used to believe I could make things a little better than the factory myself, but I have altered my thinking on that. On the vertical stabilizer fitting, the fitting is off center for a good reason! Torque and P-factor make it necessary. Some guys have centered things up and claimed a speed increase but they have big engines with offset engine mounts. I tried it about 30 years ago with a 145 on a stock mount and found I needed a LOT of right rudder on climb and also I had to bend the ground adjustable rudder tab considerably to get the ball in the center. After a few flights, I changed things back to stock and found that improved the way the airplane flew considerably. The top hole in the horizontal stabilizer attach fitting can be drilled about 1/4" lower on an early GC-1A converted to a GC-1B. Doing this, you are just duplicating what the factory did on the later serial numbers. If you can get a later part to copy, just make the fitting like the later part. The horizontal bracket has the hole centered. -- Jim

MORE ON THE STAB BEEF-UP... (040401)
From:Darrel S. Kester <dskester@worldnet.att.net>
Subject: Re: Questions for "Monty the Answer Man"
Boy, is it difficult not to put that "beef up" kit on the vertical stabilizer. But, I got a similar opinion from a FAA field inspector.

Darrel
Do you have the vertical stabilizer doublers that the Swift Assn. sold a few years ago? They were properly tapered to avoid any stress concentration and are "approvable". I have several 337's for their installation which I could copy and send to you. Those doublers are a lot harder to make than they first appear. They are curved and fabricated from 2024-0 and formed and heat treated later. There won't be any more of those from the Swift Assn. -- Jim

VERTICAL FIN OFFSETS AND CABLE TENSIONS... (100101)
Subj: Question :
From: Bill Doty <wdoty@seidata.com>
Jim, As usual I have a question .. N80572 had a full set of Corben Mods. , including the Dorsal fin , which I have removed ... I have two holes at the front attachment point of vertical fin.. One hole gives an off-set (left) of 9/16 inch and the other gives off-set of 1 inch... Can you tell me which amount of off-set is correct ?? A second question , What is proper cable tension on the rudder and ailerons ?? Bill Doty

Bill
N80572 was originally a GC-1A, so that would require the most offset of the vertical fin. Since it has now been converted to a GC-1B with the installation of the 150 Lycoming, I would go for the lesser amount of offset. Per the manual, the rudder cable tension should be 70 pounds. Be sure to check it with the tailwheel off the ground. The other 1/8" cables on the Swift should be tensioned to 20 pounds. -- Jim

VERTICAL STAB HINGE... (100101)
Subj: Upper Hinge on Vertical Stabilizer
From: Morty Lloyd <themorster@msn.com>
Monty, It was brought to my attention that the upper hinge on my vertical stabilizer which is attached to the rudder only has two bolts. Upon closer inspection I discovered that only two of the four holes were ever drilled. Should the other two holes on the upper hinge be drilled or should it be left alone? Is this common among other Swifts or am I an anomaly? Pls advise. Thanks, Morty Lloyd

Morty
Don't worry about it. The later s/n airplanes are all like that. If you think about it, the possible loading on that hinge could never exceed the strength of two AN3 bolts. Evidently that occurred to Globe and/or Temco also sometime in 1946. The early GC-1A's have four bolts in that fitting but I have never exactly determined when the factory started installing only two bolts. -- Jim

RUDDER HINGE...(010402)
Subj: rudder hinge alignment
From: Larry LaForce <LaForce55@aol.com>
Hello Jim. I just got around to cutting the lower tab from the rear spar of the vertical stabilizer. Someone had already installed the strap as reinforcement per service bulletin #26 (I am aware of the 2 bolts that interfere with the shock strut). I need to know if any misalignment is allowed between hinge points on the rudder. I have to force the bottom of the rudder over about 1/32nd to let the bolt drop through the hinge. Would this be considered normal...or do I need to try to slide one of the hinges to align all 3? As always your advice is appreciated. Larry

Larry
I wouldn't worry about 1/32". If there is severe misalignment the lower hinge fitting bolts can be loosened, and a string can be run between the 3 hinge bearings to check alignment. In a case of mismatched parts, a KS3L bearing can be installed to allow a greater nonalignment of the bearings. Just put the bolts in and make sure the rudder swings left to right freely. -- Jim

RUDDER HINGE II...(010401)
Subject: Re: rudder hinge alignment
From: Larry LaForce <LaForce55@aol.com>
Another question...what bolt length is needed for the rudder stop bolts and do they take a nut to "jam" them in place? Larry

Larry
Oh I don't know - about 3/4" I think. They are threaded all the way up to the head. Yes, they have a jam nut. Don't worry about getting too much rudder travel! -- Jim

RUDDER STUFF...(020302)
From: Swift31B@aol.com
Subject: SB 33
I am embarrassed to admit it, but I forgot something very important re: lack of rudder control on a Swift. Service Bulletin #33 tells to look for sheared rivets in the rudder horn attachment. Read SB #33. Occasionally the rudder seems OK on preflight, but with flight loads on it it will hardly deflect at all. -- Jim

RUDDER STUFF CONTINUES...(020402)
Subject: Rudder
From: Jack Gladish <gladish@adams.net>
Jim, the rudder was not hitting the rudder stop with full right rudder, it still had 15 degrees or so to go...I guess the problem is with the tail wheel spring from what I've read!?..Thats it.. don't know how else to explain it.. Could call you and talk about it!!! Jack N3321K

Jack
Did you check the rudder per SB 33? (That's where you check the rivets in the rudder horn for being shared) Perhaps the rudder cable has been replaced and is too long. Put something soft like a footstool under the aft fuselage to get the tailwheel off off the floor. Then unhook the tailwheel springs. Do you get full rudder travel now? If not, unsafety the turnbuckles on the rudder cables below the cockpit and tighten the cables to 70 pounds tension. If they bottom out and you still cannot get enough rudder tension or travel you will have to shorten the cables. You want them both the same length. Try to determine how much shorter they need to be and cut them off and reswage the thimbles in the ends. Caution: If a cable suddenly gets "longer" without being replaced it indicates the center strand is broken - if you have a broken strand of course, both rudder cables need to be replaced. I don't know your mechanical abilities, but if replacing cables is too much for you take it to an aircraft mechanic. If the tailwheel is in fact limiting your rudder travel, there are usually chains at the springs which can be lengthened. To get the springs unhooked a large vice grip can be clamped on to the spring eye. You may call me anytime. -- Jim

ED LLOYD ON JACK’S RUDDER TRIALS AND TRIBULATIONS...(020402)
Subject: Rudder
From: "Ed A. Lloyd" <edlloydaustin@juno.com>
Yo Jack. Think about this and open the Swift parts book to page 42. Shows the rudder cable rigging. (with the tailwheel off the ground). The cables from the rudder pedals, through their routing over pulleys, terminate at the bellcrank in the aft fuselage. Then there are two more short cables from the bellcrank aft that actually connect to the rudder horn. You can disconnect the tailwheel springs and the linkage that hooks the tailwheel to the bellcrank, and then all you have is a direct connection from the rudder pedals to the rudder like you see in the drawing on page 42. If you still have restricted rudder travel, then I would look at the stops on the bellcrank in the belly up forward. If those stops are set properly, then it would seem that you have a cable on the right side that is longer than it needs to be. Look at the turnbuckles just in front of station 36. Can the right turnbuckle be taken up a bit and the left turnbuckle be let out a like amount? Were both rudder cables set at 70# when you checked the cable tension? Another thing to check would be that the cables are routed over the three pulleys for the left and right cable. Hope this doesn't confuse you. Cheers.........Ed

...TAILWHEEL SPRINGS HAVE A LOT TO DO WITH RUDDER TRAVEL...(020402)
From: SteveWlson@aol.com
Subject: Rudder
If you rig the tension in the rudder cables to 70#, then attach the tailwheel chains/springs while the tailwheel is on the ground with tension on them, what happens when the tail is raised? Springs exert "more" tension on the system and in effect reduce the cable tension aft of the control arms. This is a common problem with the Swift. I guess it is one of those things that the old timers have known about for many years and it just has to come out once in a while. It is all covered in the Maintenance and Operation Information for the Swift, book available from Swift Parts. Check Page 19 for an example of what I am saying. Buzz Winslow covers it well. Happy flying... SW

CABLE TENSION... (OCT 03)
Subj: Rudder Cable tension
From: Bruce Ray <brucelray@yahoo.com>
I am in the final inspection stage for my new sticks. I read in the maint manual that the rudder cables are #70 to the rear attachment and #50 from the rear attachment on back to the rudder attachment. Is this correct? Also can you explain what it means by : ....If the tension is not #50 then lengthen the chains on the tail wheel steering mech. My A&P was inspecting and the cables from the rear attachment to the rudder attachment had no tenstion..maybe #2. That's not normal right? Thank you, Bruce

Bruce
The rudder cable tension is 70 lb. IF tension aft of the arms is less than 50 lb. THEN lengthen chain so the tailwheel springs don't take so much tension away from the cable. With the tailwheel springs disconnected, rig the rudder cables to 70 lb. tension. Hook up the springs. If the aft section is less than 50 lb. then lengthen the chains. If the aft section has no tension and you have 70 in tension on the rudder cables your springs are way too short! They have 70 lb. tension on them! -- Jim

QUICK QUESTION ABOUT RUDDER CABLES...(AUG 04)
Subj: Rudder Cable Info
From: Wyatt Honomichl <kingair100@yahoo.com>
Hi Jim, I have a quick question about rudder cable lengths. Im converting my A-model swift to a steerable tailwheel, and I need to make new cables for the added bellcrank in the tail. I would like to know if you know the lenghts of these cables in some of the data you have there, or if you have an old set of cables laying around that i can use to make a copy. Please let me know if you have anything that can help. One other question i have is, do know know of anyone that might have a set of wing root fillets for the swift. I need the Upper, Lower, and Rear ones on both sides. They do not need to be in perfect shape, since im going to be painting the plane. Thanks again, Wyatt H.

Wyatt
To make new rudder cables you don't want or need to copy old cables. Just make the cable in place and with the turnbuckle backed off, squeeze the last nicopress sleeve. If you do make the cable an inch too long or too short just make another one. 1/8" 7x19 aircraft cable is relatively cheap and you soon develop the right technique. I have a couple of upper wing fairings (the long curved ones) Boxing them up for shipping would be hard for me, do you ever come to Minneapolis/St Paul? -- Jim